handleServerRequest fell through to a JSON-RPC -32601 Method not found for several defined server -> client requests (window/showMessageRequest, window/showDocument, workspace/{semanticTokens,inlayHint,codeLens,codeAction,diagnostic}/refresh). Servers that block on a real reply -- the same failure class as the client/registerCapability hang fixed in #3029 -- could stall waiting for an acknowledgement that never came.
Reply with the spec no-op result instead: null for showMessageRequest / *Refresh, { success: false } for showDocument. Headless omp cannot honour the UI surface, but it still owes a defined response.
Fixes#3044
roboomp
ef901ecb0d